Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. These beneficial bacteria are commonly found in fermented foods and dietary supplements, supporting the gut microbiome. While many people are familiar with common strains found in yogurt, a distinct category known as Soil Based Probiotics (SBPs) has gained attention for its unique biological properties. These supplements introduce organisms historically acquired through environmental exposure to soil and uncleaned produce. Understanding SBPs requires focusing on the bacteria’s unique nature and their method of surviving the digestive process.
Defining Soil Based Organisms
Soil Based Probiotics are supplements containing microorganisms collectively referred to as Soil Based Organisms (SBOs). These bacteria are naturally occurring strains historically present in healthy soil environments and vegetation. The most common SBOs used in supplements belong to the genus Bacillus, including strains such as Bacillus subtilis and Bacillus coagulans. These organisms have long been a part of the human diet through the consumption of food grown in the earth.
Modern SBP supplements do not contain raw soil or dirt. The specific beneficial strains of SBOs are isolated and cultivated in controlled laboratory settings. This purification process ensures the strains are safe, effective, and free from potentially harmful contaminants found in natural soil. The final product is a precise, concentrated dose of the desired microorganisms.
Survival Mechanism and Gut Transit
The primary biological distinction of Soil Based Organisms is their ability to form a protective structure known as an endospore. This spore is a metabolically dormant, seed-like form the bacteria enter when faced with unfavorable environmental conditions. The complex outer coat is highly durable, allowing the bacteria to withstand extreme conditions that would typically destroy other microorganisms.
This resilience allows SBOs to survive the harsh environment of the upper gastrointestinal tract. The spores remain intact against the low pH and high acidity of the stomach, as well as the digestive enzymes and bile salts present in the small intestine. They are protected until they pass through this difficult transit phase.
Once the spores reach the lower gastrointestinal tract, where the environment is more neutral and contains necessary nutrients, a process called germination begins. The spores rapidly “awaken” from their dormant state, shedding their protective coat to become active, vegetative bacteria. This mechanism ensures a high percentage of ingested microorganisms successfully colonize the lower intestine, where they exert beneficial effects.
Key Differences from Traditional Probiotics
Traditional probiotics are primarily composed of lactic acid bacteria (LAB) from the Lactobacillus and Bifidobacterium genera. The first major distinction is taxonomy, as SBPs use Bacillus species while traditional strains are associated with fermented foods like yogurt and kefir.
The second difference is resilience, specifically the ability to form spores. Traditional LAB strains are non-spore-forming and exist only in the active state. This makes them highly susceptible to degradation by stomach acid and digestive enzymes, significantly reducing the viable cells that reach the lower intestine. SBOs use the spore form as a survival strategy, ensuring higher rates of survival through the digestive tract.
The third distinction is shelf stability, a direct outcome of the spore-forming capability. Traditional probiotics are vulnerable to heat, moisture, and light, often requiring refrigeration to maintain potency. SBP supplements, due to their dormant, resilient spore state, are typically shelf-stable and do not require cold storage. This hardiness makes them a practical choice for travel.
Considerations for Supplementation
Consumers should focus on product sourcing and the specific strains included. Choose products from reputable manufacturers who provide documentation of third-party testing, which verifies the identity, purity, and potency of the lab-cultivated organisms.
Dosage is measured in Colony Forming Units (CFUs), indicating the number of viable bacteria. Due to their higher survival rate, SBP supplements may contain a lower CFU count than traditional non-spore-forming varieties while still delivering an effective dose. SBP products are often favored by individuals seeking a more resilient option or those sensitive to traditional Lactobacillus and Bifidobacterium strains.
SBOs are considered safe when taken as directed. However, consult a healthcare professional before beginning a new regimen, especially if you have underlying health conditions or are immunocompromised.